The present invention is generally directed to a treatment system for a workpiece and, more particularly, to a treatment system having one or more fluid tanks and a conveyor assembly to translate and rotate vehicle bodies into and out of the fluid tanks.
The material handling art includes numerous systems for transporting workpieces through numerous types of manufacturing facilities. One area of interest is the manufacture and assembly of vehicles, particularly vehicle bodies. When assembling a vehicle body, it is common to move the bodies through a predetermined sequence of production areas via conveyors. The conveyors can take numerous forms including belt, chain, electrified rail, and skillet systems. The selection of an appropriate conveyor for a production area is dependent on a variety of factors including maintaining through-put rates for the system and the nature of the assembly, manufacturing, or production processes to be performed on the body in each area.
Vehicle body manufacturing facilities commonly include a treatment area prior to body painting. In the treatment area, the vehicle body is dipped in treatment tanks to clean the body and to apply a coating. For example, the vehicle body may be conveyed through a multiple stage treatment area which commonly includes phosphate and E-coat applications. It is generally known in the art that the treatment of the vehicle bodies in the treatment area is enhanced by complete immersion of the vehicle bodies for a predetermined time in the fluid filled tanks. Thus, the vehicle bodies may be attached to a conveyor or rotating mechanism that rotates the vehicle body into the tank. For example, one conventional system (disclosed in U.S. Pat. No. 6,419,983) touts the continuous movement of workpieces along a direction of movement while rotating the workpieces in the direction of movement and about an axis aligned across the direction of movement. The workpiece is completely introduced into and later removed from the treatment tank as a result of the rotation. However, like other prior art systems, the conveyor used in this system suffers from numerous disadvantages. For example, the conveyor is incompatible with conveyor assemblies that may be used in other areas of the manufacturing facility thereby requiring transfer of workpieces between different conveyor assemblies before and after treatment. Moreover, the prior art conveyor uses a pair of laterally spaced drive chains that must be moved in a synchronous manner to ensure smooth workpiece movement through the treatment area.
Notwithstanding the number of different approaches to transporting workpieces through dipping treatment areas, the art has not adequately addressed many manufacturing concerns including providing a treatment system conveyor assembly that facilitates transportation of the workpieces from and to other treatment applications, accommodating the relatively extreme loads created by rotating vehicle bodies, and improving the ability to index or otherwise control the movement of workpieces through the treatment area.